Stomach problems from lemons?

I’ve been drinking water with the juice from half a lemon for dinner the past few nights, partly because it’s good for bloating and I’ve got my, er, time of the month, and partly because I just like the taste of it.

But tonight I’ve had an acidic stomach and while it’s not quite queasy, it’s uncomfortable. I’m starting to suspect the lemon juice.

Has anyone had any acidic stomach problems from lemon juice?